Systems that sense acoustic or mechanical energy are used in a variety of applications, including, but not limited to, oilfield drilling and maintenance, underwater monitoring, and maintenance of large structures, such as mines, bridges and elevators. In these sensing systems, sensors take measurements at their respective locations. The measurements taken by the sensors are compiled and may be used to provide information regarding the structure(s) or locations that are monitored.
One class of sensor is optical in nature. An optical sensor can generate optical signals and can direct measured information to the processor via one or more optical fibers. One issue facing some optical fiber-based sensing systems is channel count—that is, the number of different streams of optical data that may be transmitted at a time. In one approach, sensors can be optically coupled to an optical excitation or detection apparatus using a one-to-one arrangement including a respective optical fiber for each sensor. However, such an approach may preclude use of more than a handful of optical sensing channels because the number of optical fibers may be limited due to cost or space constraints. Prior attempts to address this issue have resulted in sensing systems that are unacceptably insensitive to swings in acoustic or mechanical energy.
It should be understood, however, that the specific embodiments given in the drawings and detailed description thereto do not limit the disclosure. On the contrary, they provide the foundation for one of ordinary skill to discern the alternative forms, equivalents, and modifications that are encompassed together with one or more of the given embodiments in the scope of the appended claims.